Do my MPGs seem normal or could there be something wrong?

[zeus2120]

I finally pulled the trigger on joining the Ramily! I picked up a loaded 2014 Bighorn CC 5'7 Box 4X4 with 28,000 miles. I didn't buy it for gas mileage, but I feel like it should be better. I want to know if anyone thinks there could be a problem and what you'd do to troubleshoot.

I took a 175 mile highway roadtrip yesterday. Filled up right before getting on the highway and again when I got off. I averaged 68 mph on the trip. Five people, probably about 800 pounds total. I do have the tow package, 3.92 rear axle, and running boards. Temperature outside was 51 degrees. I averaged 15.31 MPG hand calculated. Does that seem low for a fairly nice day and all highway? If so, what could be causing such bad mileage when so many people on here claim to get 20+ at highway speeds? My hand calculated mixed driving before the roadtrip was 12.2mpg. Again, seems quite low. I drove the whole way with cruise control. Would love some input!

Thanks!

 

[Am3gross]

if its the 6.4 it sounds about right... if its the 5.7 it seems maybe a little low...

 

[R.L.K.]

6 speed or 8 speed

 

[zeus2120]

It's the 5.7 with the 8 speed. The computer said 16.8mpg when I filled up, so off by about 1.5mpg. Truck runs great, shifts smooth -- just a little disappointed about 15mpg highway when I used cruise the whole way.

 

[dunney]

Vouching for my 2011 5.7, I do have to admit my mpg's can vary wildly, depending on many factors. Wind direction, weight in the truck, stuff in the bed, will all affect the mileage. I watch the fuel economy in the menu. Do you have that option? Do you have the little "ECO" light that comes on when you are getting maximum fuel economy?

I schlepped out to OH to pick up a trailer and drove it back home here to NH. Gas mileage WITH THE TRAILER, at 80mph, with a 10 to 20mph tail wind, I got 23 mpg. Transporting an engine drops it to 17mpg. Adding 600 pounds of weight (sand, salt, and water bag) to the rear for winter driving drops it to 15mpg. Basically any wind other than at my back drops me back into the teens. It's like a sailboat for Christ's sake.

Speed definitely affects it too. Although noone wants to, if you can average 50 mph, you can probably increase mpg 25 to 50 %. Check you tire inflation too. The closer you can get them to 40 PSI certainly helps, although your tires and traction may not like it.

 

[Motivology]

I think you should be getting more highway mpg with the 8 speed. I have a 5.7 Hemi with 6 speed (truck's 2012) and my avg mpg according to computer is ~14. And that's about 65% city and 35% highway driving.

One question though, was your roadtrip pretty flat or were there hills you had to climb?


Cruise control on + hill climb = mpg killer.

 

[Hemi395]

Seem like it should be a little higher than that with the 8spd...

 

[Hemi395]

Cruise control on + hill climb = mpg killer.

^This. Mine gets considerably worse mpg when using the cruise on a hilly highway.

 

[zeus2120]

if its the 6.4 it sounds about right... if its the 5.7 it seems maybe a little low...

6 speed or 8 speed

Vouching for my 2011 5.7, I do have to admit my mpg's can vary wildly, depending on many factors. Wind direction, weight in the truck, stuff in the bed, will all affect the mileage. I watch the fuel economy in the menu. Do you have that option? Do you have the little "ECO" light that comes on when you are getting maximum fuel economy?

I schlepped out to OH to pick up a trailer and drove it back home here to NH. Gas mileage WITH THE TRAILER, at 80mph, with a 10 to 20mph tail wind, I got 23 mpg. Transporting an engine drops it to 17mpg. Adding 600 pounds of weight (sand, salt, and water bag) to the rear for winter driving drops it to 15mpg. Basically any wind other than at my back drops me back into the teens. It's like a sailboat for Christ's sake.

Speed definitely affects it too. Although noone wants to, if you can average 50 mph, you can probably increase mpg 25 to 50 %. Check you tire inflation too. The closer you can get them to 40 PSI certainly helps, although your tires and traction may not like it.

Thanks for the input. Yes I do watch the eco light, just seems like it doesn't illuminate for a very long time. I tried to keep my speed under 70 for the most part to maximize fuel economy. I do notice that at about 40-45 mph the computer shows mpgs in the 30s.

 

[zeus2120]

I think you should be getting more highway mpg with the 8 speed. I have a 5.7 Hemi with 6 speed (truck's 2012) and my avg mpg according to computer is ~14. And that's about 65% city and 35% highway driving.

One question though, was your roadtrip pretty flat or were there hills you had to climb?


Cruise control on + hill climb = mpg killer.

It was hilly. Nothing drastic but it definitely was not flat. For those of you familiar, it was I 71 South starting in Cleveland, Ohio.

 

[blackbeautyhemi]

Don't forget the winter blend fuel usually lowers your mpg's also.

 

[7777xm]

I have the same setup as you I think. 2014 CC 5.7 4x4 8 speed w/3.92

Your MPG sounds low. My city is 15 and that's with my hemi foot!

At 65 or so, I get 20 to 21 MPG. My EVIC is usually with a 1/2 MPG.

I recently took a trip to IL, spent much of the drive above 90 mph, averaged 74 mph, and got high 18s. There was a lot of WOT runs too.

Yours seems way low.

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[zeus2120]

I have the same setup as you I think. 2014 CC 5.7 4x4 8 speed w/3.92

Your MPG sounds low. My city is 15 and that's with my hemi foot!

At 65 or so, I get 20 to 21 MPG. My EVIC is usually with a 1/2 MPG.

I recently took a trip to IL, spent much of the drive above 90 mph, averaged 74 mph, and got high 18s. There was a lot of WOT runs too.

Yours seems way low.

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Do you run 87 or 89 octane? I wonder if your higher outdoor temp makes a large difference. I hope I can get these mpgs up a bit!

 

[7777xm]

Do you run 87 or 89 octane? I wonder if your higher outdoor temp makes a large difference. I hope I can get these mpgs up a bit!

89. Colder is better for MPG. Denser air.

I wonder if yours has a tune you didn't know about?

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[zeus2120]

89. Colder is better for MPG. Denser air.

I wonder if yours has a tune you didn't know about?

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I've only filled up twice and used 87. Next tank will try 89 and see how it goes.

 

[7777xm]

What tires are you running? Is it lifted or leveled? Underneath the front bumper, does it still have the air dam valance? Often overlooked, but how's the air filter looking?

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[zeus2120]

What tires are you running? Is it lifted or leveled? Underneath the front bumper, does it still have the air dam valance? Often overlooked, but how's the air filter looking?

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OEM tires, brand new that the dealer put on last week. Not lifted or leveled, bone stock. Not sure about the air dam valance. Will have to check that out. What is that for / what does it do? Air filter, not sure, haven't looked. Just bought it last week.

 

[69GWC]

Wonder if your truck could be stuck in 4wd.?

 

[RJP]

I've got a 2013 quad cab sport (5.7) with 38,000 miles and get 14 in town and anywhere between 19 to23 on interstate using cruise. Really varies with wind mostly.

 

[smurfs_of_war]

If you just bought last week, then it has had 28000 miles of someone else's driving habits. I'd let it learn you a bit before I worried too much

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